As disclosed in said co-pending application it is desirable to seal the relatively hot manifold tightly against the adjacent mold plates which supports the nozzle housing while blocking the transfer of heat from the manifold to mold plates for well known reasons.
In the co-pending application the structure for sealing the manifold and maintaining thermal insulation are the cup-shaped expansion elements 12 and 13.
A further example of prior art expansion elements are disclosed in U.S. Pat. No. 4,268,240 in that a cup-shaped element 20 (termed a cylinder) abuts one side of a floating manifold 22 and is bottomed in a cover plate or back plate 10.
A second expansion element 24 (termed a nozzle) abuts the opposite side of the manifold and includes nozzle housing leading to mold plates 12 and 13.
While these prior art thermal expansion arrangements are operable there is constant activity to increase the integrity of the seal, improve thermal insulation, and extend the stroke or deflection of the expansion elements while minimizing the number of critical dimensions that must be met in fabricating the various piece parts.